function calTotal(quantity, price, totalarea, totalfield){
    total=quantity * price;
    document.getElementById(totalarea).innerHTML=total;
    document.getElementById(totalfield).value=total;
}

function showPayment(selected) {
	var current = selected;
	var all_payments = new Array("creditcard", "paypal", "cheque");

	for (var i=0; i<all_payments.length; i++) {
		activeElement = document.getElementById(all_payments[i]);
		if (activeElement.style.display != "none") {
			activeElement.style.display = "none";
		}
	}

	document.getElementById(current).style.display = "block";
}

function changeCardType(cardtype){
	document.getElementById('card_type').value=cardtype;
	all_cardtype=new Array('visa','master','amex');
	for (var i=0; i<all_cardtype.length; i++) {

		document.getElementById(all_cardtype[i]).style.opacity = "0.2";
		document.getElementById(all_cardtype[i]).style.filter = "alpha(opacity=20)";

	}
	document.getElementById(cardtype).style.opacity = "1";
	document.getElementById(cardtype).style.filter = "alpha(opacity=100)";
}

function detectMenuOverflow(){
	var obj=document.getElementById('header_nav');
	var liObj=obj.getElementsByTagName("li");
	var totalwidth=0;
	for(var i=0; i <liObj.length; i++){
		totalwidth=totalwidth+liObj[i].offsetWidth;
		if(totalwidth>obj.offsetWidth){
			liObj[i].style.display='none';
		}
	}
}


function php_urlencode (str) {
    str = escape(str);
    return str.replace(/[*+\/@]|%20/g,
        function (s) {
            switch (s) {
                case "*": s = "%2A"; break;
                case "+": s = "%2B"; break;
                case "/": s = "%2F"; break;
                case "@": s = "%40"; break;
                case "%20": s = "+"; break;
            }
            return s;
        }
    );
}